Parasitic draw test reading 0, help.

[AN292]

Occasionally coming across a dead battery overnight.

The battery is a few months old, the alternator is about a year old.

Turning the truck on, I go down to 10.03 volts, then 13.85 when it's on.

Off, I get 12.04 volts.

This was just after I found it dead and jumped it, so I might have to go and charge the battery and do this all over again. But that explains the low numbers for now.

Anyway, the draw test is reading 0. I have it connected as follows:

- Removed negative cable
- Red probe onto negative cable
- Black probe on negative terminal.

I have cycled through Amps and MA, I also moved it to DC, and it's still 0. I know it says AC on the meter but trust me, it says 0 every which way.

 

[swathdiver]

Get your battery onto a charger or tender to bring it up to a full charge. If you are not driving very often or far lately, the battery is not getting fully re-charged after sitting. The computers in these things wake up, do some work and go back to sleep all the time. It's possible that the new battery was not fully charged or has a bad cell but get it charged up first and then see what needs doing, if anything.

 

[Fless]

This isn't meant to be rude... you should have some kind of draw all the time. Desired draw asleep is 50mA or less, but when you first put the meter in circuit it will draw much more than that, and you can watch the module go back to sleep by seeing the draw go down. I wonder if the connection at the battery isn't making good contact. I usually use a bolt screwed into the battery to be sure. I would start with the 10A test to be sure about not overdrawing through the meter.

So, as a test, take the meter out of circuit, set the selector to ohms, connect your leads to the two righthand jacks, and touch the ends of your leads together. If it doesn't read 0 ohms (or 0.1, some reasonable resistance for a short), then one or both leads are bad, or something's wrong with the meter.

If that works, check the internal fuse(s) for continuity; it could be blown. Usually there is at least a fuse for the 10A measurement.

If you get to the point of reading mA (but depending on the instructions in the manual) the red lead should be moved to the jack circled in green, and the selector to mA:

 

[iamdub]

Occasionally coming across a dead battery overnight.

The battery is a few months old, the alternator is about a year old.

Turning the truck on, I go down to 10.03 volts, then 13.85 when it's on.

Off, I get 12.04 volts.

This was just after I found it dead and jumped it, so I might have to go and charge the battery and do this all over again. But that explains the low numbers for now.

Anyway, the draw test is reading 0. I have it connected as follows:

- Removed negative cable
- Red probe onto negative cable
- Black probe on negative terminal.

I have cycled through Amps and MA, I also moved it to DC, and it's still 0. I know it says AC on the meter but trust me, it says 0 every which way.

What swathdiver and Fless said. If you really wanna test it, open a door so your dome lights come on. That's certainly a draw but it shouldn't be anywhere near 10 amps.

 

[Fless]

What swathdiver and Fless said. If you really wanna test it, open a door so your dome lights come on. That's certainly a draw but it shouldn't be anywhere near 10 amps.

In my Hoe the interior lights are about 4A.

 

[iamdub]

In my Hoe the interior lights are about 4A.

Nice to put a number on it. Whatcha betting- poor connection or popped fuse in the meter? My bet is on the fuse.

 

[Fless]

Nice to put a number on it. Whatcha betting- poor connection or popped fuse in the meter? My bet is on the fuse.

I would agree; and most of those fuses aren't that available or cheap. If needed, might have to get one (or two) online. Seemed to be reading voltage okay so the leads are probably good.

 

[AN292]

the Klein wasn’t getting a reading. My dads old fluke is showing 2.5 amps. Turns out it’s my ignition cylinder. You can accidentally bump it without the key, and the dash lights come on. If you aren’t paying attention when you get out of the car it’ll draw heavily.

Solved, thanks for the help.

 

[corvette744]

the Klein wasn’t getting a reading. My dads old fluke is showing 2.5 amps. Turns out it’s my ignition cylinder. You can accidentally bump it without the key, and the dash lights come on. If you aren’t paying attention when you get out of the car it’ll draw heavily.

Solved, thanks for the help.

Thats why i always test the meter first or just use old school test light first to see if it lights up.Easiest way and quickest to see if you have a draw.

 

[rockola1971]

Who wants to learn a Vacuum tube guitar amplifier trick for measuring current without having to do it in series and disconnecting this and that and trying to get your meter leads connected to this and that?

Goto mouser.com and order up (1) or more if you want some spares of a precision 1 ohm resistor. You touch your negative meter lead to ground. Touch positive meter to one end of the resistor and the other end of the resistor to whatever wire or connection that you want to read the current flow. Have meter set on DC VOLTS (*NOTE NOT AMPS*). The reading on your meter will be in volts but because of ohms law and the fact you are using a precision 1/2w or bigger 1 ohm resistor the reading can be converted to amps by moving the decimal point only!